当对象被销毁的析构函数被调用。对于自动（堆栈）变量，把它留给它的范围后，就是所谓的（ {} ）。了解更多关于自动变量的。

The destructor is called when the object is destroyed. For automatic (on stack) variables, it's called after leaving its scope ({}). Read more about automatic variables.